Griffin Smith 81839aa6ae feat(): Allow creating database snapshots ... Add a `create_snapshot` function, that creates a RocksDB database snapshot from the given database handle and returns it. There's a pretty fantastic amount of horribly unsafe Rust going on here - primarily caused by the fact that the rust-rocksdb snapshot type is, unlike Iterator or ColumnFamily or any of the other types that really *should* be, parametrized by the lifetime of a borrowed reference to its owner database. The abstraction provided by Rustler doesn't allow non-static lifetime-parametrized struct types to be returned back to Erlang as resources, for some technical type-mismatch reasons but also practically because relying on the Erlang garbage collector to free our stuff doesn't fit at *all* with rust's lifetime model. The workaround here is to use `mem::transmute` (I told you it was crazy...) to turn the snapshot reference from a `Snapshot<'a>` to a `Snapshot<'static>`, and pass *that*, along with a held ARC reference to the owning DB, to Erlang, and then when the Erlang GC decides it's time to free the snapshot, go *back* to a first unbounded, then elided lifetime to force the snapshot to be dropped. I've done some cursory checking and regular operation (creating a snapshot from a process then letting that process die) appears to not leak the snapshots, but we should keep an eye on this to make sure we don't have any leaks (or worse) in the future. As a further note, the bit that parses out the argument for the NIFs that now accept *either* a DB or a snapshot is a little mucky - that should be revisited at a later date to see if we can clean it up a little.		2017-11-30 15:30:06 -05:00
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rox	feat(batch): Impls batch merging	2017-06-22 17:29:50 -04:00
rox_test.exs	feat(): Allow creating database snapshots	2017-11-30 15:30:06 -05:00
test_helper.exs	initial commit	2016-08-08 11:51:04 -04:00
utils_test.exs	feat(): add auto opening of column families, streaming, enumerable and collectable	2017-03-21 14:09:51 -04:00